Currently, there are a large number of methods and devices designed to detect blood glucose levels and particularly hypoglycemia in human beings with diabetes mellitus. The traditional method for monitoring glucose levels is by “finger sticking” and measuring the glucose level from the blood expressed. Avoiding the pain and discomfort of “finger sticking” has promoted the development of the non-invasive techniques such as measuring glucose concentration using the absorption of light in the infrared spectrum. Another approach has been subcutaneous fluid testing using either a disposable subcutaneous glucose monitor or the relatively permanent implantation of glucose sensors. Additionally, a noninvasive method has been developed in which impedance spectroscopy or similar methods are used to measure glucose concentrations. These various methods and devices have suffered in the reliability of the test results. The most accurate present means of repeatedly and accurately monitoring blood substances is by an indwelling intravascular catheter. The problem with these is that their useful time is limited by tissue breakdown and infection.